Electron beam irradiation-induced reduction of SnO₂ deposited on TiO₂(110) surfaces

SnO₂ was deposited by pulsed laser deposition at room temperature in ultrahigh vacuum on TiO₂(110) surfaces having different chemical states, either fully oxidized TiO₂(110)-(1 × 1) or partially reduced TiO₂(110)-(1 × 2). For both cases, just after deposition, Sn was found to be in an oxidized state. When the SnO₂ on TiO₂ surfaces was irradiated with an electron beam, SnO₂ was completely reduced into a metallic state, with the reduction rate of SnO₂ on the TiO₂(110)-(1 × 2) surface being at least 3 times higher than that on TiO₂(110)-(1 × 1). Scanning tunneling microscopy images of SnO₂ on a TiO₂(110)-(1 × 2) surface, measured before and after electron beam irradiation, suggest that, while SnO₂ is reduced into a metal, the reduced TiO₂(110)-(1 × 2) surface is simultaneously reoxidized, consequently decomposing the (1 × 2) reconstruction.